Alert Warns Of Possible Encephalitis Epidemic

The Health Department has placed Palm Beach County on alert for a possible epidemic of St. Louis encephalitis, a potentially lethal brain infection spread by mosquitoes.

``People need to be very cautious about avoiding mosquito bites,`` Health Department epidemiologist Karlette Peck warned Monday. ``It can be very serious.``

St. Louis encephalitis is a viral infection of the central nervous system that is spread to people by night-biting mosquitoes that have bitten infected birds and other animals.

The disease, which can be fatal in some cases, usually is most severe in people older than 50. No cases of the disease in humans have been confirmed in Florida so far this year.

The Health Department issued the epidemic alert after confirming Friday that half of a flock of six ``sentinel`` chickens kept in Jupiter had been infected with the encephalitis virus.

Because the mosquitoes that carry encephalitis are more likely to bite birds than people, each county keeps small flocks of chickens that are tested frequently to provide an early warning of the presence of the disease.

Palm Beach County is the 11th county in the state to issue an epidemic alert for St. Louis encephalitis this fall.

Peck said the alert means the Health Department is urging residents to remain indoors whenever possible at dusk or later. People who must go outside at night should wear protective clothing and use mosquito repellant, she said.

Residents also should remove stagnant water from ponds and household containers where mosquitoes can breed, and they should make sure that window screens are in good repair, she said.

Peck said the county mosquito control office began spraying insecticide in Jupiter neighborhoods this weekend. Control efforts also have been intensified countywide, she said.

Although no confirmed human cases of St. Louis encephalitis have been reported in Florida since 1983, a Lee County woman suspected of having the disease is being monitored by health authorities, said Linda McCaig, an epidemiologist with the Florida Department of Health and Rehabilitative Services.

McCaig said the first epidemic alerts this year were issued Oct. 7 in Lee and Collier counties. The other counties under alert include Dade, Indian River, St. Lucie, Martin, Hendry, Sarasota, Charlotte and Highlands, she said.

In Palm Beach County, the Health Department plans to test the blood of three people who developed encephalitis in October and November to determine whether their illnesses were caused by the St. Louis encephalitis virus, Peck said. ``There are hundreds of things that can cause encephalitis,`` she said.

Peck said that unseasonably warm and rainy weather this fall provided a good breeding environment for the mosquitoes that spread encephalitis. ``I`m hoping the weather will cool down and get dry,`` she said. ``We might luck out and wipe out the mosquitoes.``

The last epidemic of St. Louis encephalitis in Florida occurred in 1977 when 78 people in 20 counties in the southern and central parts of the state contracted the disease. Eight victims of the disease died.

Palm Beach County experienced an outbreak of St. Louis encephalitis in 1979 with five reported cases. The last reported case in Florida occurred in 1983 in Hillsborough County.

ST. LOUIS ENCEPHALITIS

WHAT: A viral infection of the brain.

SOURCE: People contract the disease by being bitten by mosquitoes that have been infected by birds and other animals.

SEVERITY: A potentially life-threatening disease that can leave permanent brain damage. The disease usually is more serious in those over 50. Infants and small children are less likely to have severe symptoms.

TREATMENT: There is no specific treatment, but medical care is needed to help reduce fever and pressure around the brain that sometimes is associated with the disease.